Acceleration responsive device



Feb. 23, `1943. J. P. BRANDT I ACCELERATION RESPONSIVE DEVICE 3Sheets-Sheet 1 Filed Oct. 51. 1940 Fig.

Fig. 2.

lnvzni'or: James P. brondi l reb. 23, 1943. J. P. BRANDT ACCELERATIONRESPNSIVE DEVICE Filed Oct. 51. 1940 5 Sheets-Sheet 2 Eig. 5.

Fig.4

lnwznror: James P. Brand? J. P. BRANDT ACCELERTION RESPONSIVE DEVICE medoct. s1. 1940 5 Sheets-Sheet 3 Fig? \nvzn'for: James P. brand# PatentedFeb. 23, 1943 ACCELERATION RESPONSIVE DEVICE James P. Brandt,Bellflower, Calif., assigner to Shell Development Company,

San Francisco,

Calif., a corporation of Delaware Application October 31, 1940, SerialNo. 363,642

(Cl. 20D-52) 4 Claims.

This invention is an acceleration responsive device, and has for itsobject to actuate a control Whenever predetermined acceleration occurs.

More particularly, it is an object of the invention to retain anoperating means in inoperative position throughout normal transition ofa movable element, and to shift the operating means to operativeposition whenever there is predetermined acceleration of the movableelement, with -a control actuated responsive to shifting of the thebeam, but which in the event of abnormal acceleration of the beam isshifted to operative position for actuating a control which arrestsoscillation of the walking beam.

The invention is thus particularly applicable as a safety device for thewalking beam of a deep well pump, in that in the event of oscillation ofthe walking beam at excessive speed, as may result from breaking thestring of sucker rods which is reciprocated by the beam, a control isactuated for stopping the driving mechanism for the walking beam beforeexcessive damage has been done.

Further objects of the invention will be readily understood from thefollowing description of the accompanying drawings, in which:

Fig. 1 is a side elevation of the walking beam and driving mechanism fora deep well pump, with the acceleration responsive device mounted on thewalking beam.

Fig. 2 is a longitudinal vertical section through a preferred embodimentof the acceleration responsive device.

Fig. 3 is a plan view of the same embodiment of the accelerationresponsive device with its cover broken away.

Figs. 4 and 5 are transverse sections on the lines 4-4 and 5-5,respectively, of Fig. 3.

Fig. 6 is a longitudinal vertical section through another modificationof the acceleration responsive device.

Fig. '7 is a cross-sectional view taken along the lines I 'I of Fig. 6.

The invention is particularly applicable and is therefore illustratedand described in connection with the walking beam of a deep well pump.For instance, as shown in Fig. l, a walking beam I is adapted foroscillation for reciprocating a string of sucker rods 2 which extendinto the well for operating the pump, the walking beam being oscillatedby a usual crank and pitman 3 4, and the crank 3 being rotated bydriving mechanism Which may be any suitable prime mover, indicated as aninternal combustion engine 5. 1Breferably mounted above the fulcrum 6and on the walking beam I is the present acceleration responsive device,schematically represented at 9.

Referring to Figs.v 2-5 showing a preferred embodiment of the presentinvention, a casing IU having a removable cover i I houses theacceleration responsive device. An operating means I2 is vmounted in thecasing and is normally retained in inoperative position as shown at Fig.2, but responsive to predetermined acceleration of the walking beam isshifted t-o one or the other of operative positions for actuating acontrol which in the illustrated embodiment of the invention is anormally open electrical circuit I3.

When the electrical circuit has been closed by shifting the operatingmeans. to one or the other of its operative positions, it may indicatethat excessive acceleration has occurred, e. g. by providing anelectrically responsive signal device (not shown) in the electricalcircuit, but as a preferred arrangement closing the electrical circuitstops the driving mechanism for the walking beam I, e. g. byshort-circuiting the ignition system of the internal combustion engine 5or by energizing a suitable electrically responsive cutoff (not shown)for whatever type o1 prime mover may be employed. v v The operatingmeans I2 is ,shown as ,arelatively heavy sphere, normally supportedbetween proximate ends of blocks Id which are mounted in the respectiveends of the casing Iii. The

vblocks are slidably mounted for adjusting the spacing between theirproximate ends, and for this purpose have depending screws I5 which areslidable in slots I6 in the base of the casing I0, with retaining headsI'I threaded on the screws and slidable in recesses I8 in the undersideof the casing. A spring I tends to longitudinally space the blocks I4,and adjusting bolts 20 are threaded through the respective ends of thecasing and engage the respective blocks for projecting them toward oneanother against the tension of their spring.

The upper surfaces of the blocks I4 are longitudinally grooved as shownat 2l, and intermediate their ends the upper surfaces of the blocks arerecessed as shown at 22. The sphere I2 is normally positioned betweenthe longitudinally spaced blocks, resting upon supporting edges 23 whichare formed at the junction of the grooves 2| with the end surfaces ofthe blocks, with an appreciable mass of the sphere depending from thesesupporting edges into the space between the proximate ends of theblocks. The sphere is thus gravitationally` retained in this normalinoperative position during longitudinal tilting of the casing III withthe walking beam I, as long as this tilting movement is not acceleratedbeyond a predetermined maximum.

In the event of predetermined acceleration, inertia of the sphere I2dislodges it from its normal inoperative position andtilts it over one.or the other of the supporting edges 23 so asto roll the sphere alongthe correspondingsgroovelI and into the corresponding recess 22, withthe relatively steep end walls of the recess then retaining` the spherein the recess. The acceleration which will cause this dislodgment. ofthe sphere'may` be regulated by adjusting` thelongitudinal-spacing ofthe blocks I4 so that when the sphere-is in normal inoperative positiona greater or less portion of its mass lies below the plane cf thesupporting edges 2'3.

When the sphere has4 rolled into one or the other of the recesses 22l itactuates the control which in the present instance is shown as theelectrical circuit I3. For this purpose', the recesses 22VA openlaterally through the sides of the blocks I4 and a pair of transverselyspaced electrical contacts project into each of the recesses 22 throughthe respective side walls of thecasing I0, these pairs oftransverselyspaced contacts being shown at 25a-25h. The recesses 22 areof a length to aline Withthe respective'pairs of electrical contactsirrespective of the longitudinal adjustment ofthe blocks I4; and thecontacts of each'pair aretransverselyV spaced so that in any position towhich the sphere I2 may rollin a recess 22 it will engage and bridge thepair of contacts.

The sphereY I2' is a metal sphere so that when bridging either pair ofcontacts it forms an electricalv conductor therebetween; and the pairsof contacts 25a-Zware in series in the circuit I3, as,n shown atYI3a--I3b, so that. an electrical circuitr iscompleted whenever thesphere I2 bridges f.

eitherpair of contacts'. In the illustrated embodiment of the inventionwherein closing the circuit I3short-circuits the ignition system of theinternal combustion engine 5', the sphere I2 may be grounded .via' itssupportingvr block I4 and the. cas- A ingy l'when bridging a pair ofcontacts; or, if completing the electrical circuit energizesY anelectrically responsive cut-off for some other type of prime mover,insulation may be providedY in the `1e`cesses22 forpreventinggroundingof the sphere I2.when bridgingeither pairoficontacts, and the contacts may also be suitably` insulatedfrom thecasing: I0.

The. cover. II for the casing I is adapted for detachable mounting onthe casing. As. an instance, screws 3IJ may extend through slots 3| independing lugs of the cover and may be threaded through the side Wallsofv the casing I0 so as to engage and clamp the blocks I4`inlo-ngitudinally adjusted position, with wing nuts 32 threaded on theouter ends ofthe screws and clamping against the lugs of the cover forsecuring the cover in place.

The acceleration responsive device is mounted on. the walking beam I sothat when the beam is horizontal the casing Ill is also horizontal, andwhen the sphere I2 is in normal inoperative position resting upon thesupporting edges 23 the center of the sphere is vertically alined withthe axis of oscillation of the walking beam. The casing I may be securedin place by bolts 35 extencng through ears 36 of the casing, and spiritlevels 31-38 may be provided on the cover I I for indicating when thecasing II) has been so mounted on the walking beam that it is exactlyhorizontal when the walking beam is horizontal.

The oscillation responsive device is thus adapted for oscillation withthe walking beam; and by adjusting the bolts 20 the longitudinal spacingof the blocks I4 may be adjusted so that during normaloscillation of thewalking beam the supporting edges 23 retain the sphere I2 in normalinoperative position, but in the event of predetermined abnormalacceleration of the walking beam, as may result from breaking the stringof sucker rods 2, the sphere I2 is dislodged and rolls along one or theother of the grooves 2I and into the cooperating recess 22 for bridgingthe pair of contacts 25a or 251), thereby closing the electrical circuitI3 for stopping the prime mover 5 and thus arresting oscillation of thewalking beam before excessive damage has been done.

In another embodiment, as shown in Figs. 6 and 7, wherein like numeralsindicate like parts, in place of the two blocks I4 of the rst embodimentthere is one block I4a rigidly fastened to the casing lila by bolts 49and having a transverse slot 4I approximately midway between therecesses 22. Transverse plates 42 adapted to support the sphere I2 arepivoted from the edges of the slot4I by means of pins 44 and areadjustably positioned by means of slotted arcuate ears 45 which dependfrom the unpivoted edge of the plates 42. Screw bolts 46 passingvthrough the slotted arcuate ears 45 and screwing into the block I 4a areprovided to hold the sphere supporting plates 42. in the desiredposition. It may be seen that the plates 42 may be readily adjusted toregulate the depth of the resting place forv the sphere and thereby theacceleration which will cause the dislodgment of the sphere I2 intoeither ofthe recesses 22 where the sphere I2 Willbridge a pair of thetransversely spaced electrical contacts 25a and 251) projecting intoeach of the recesses 22.

I claim as my invention:

1. In an acceleration responsive device, longitudinally spaced blocksadapted for oscillation, the upper surfaces of the blocksbeinglongitudinally grooved with recesses intermediate the ends of thegrooves, asphere normally resting upon supporting edges at the ends ofthe grooves and depending between proximate ends of the blocks, meansfor adjusting longitudinal spacing of the blocks, and a pair oftransversely spaced electricalY contacts projecting into each recess,the sphere being adapted for dislodgment from its normal inoperativeposition responsive` to prede,- termined acceleration of the blocks, soas to roll along one or the other of the grooves and into thecorresponding recess for bridging a pair of the contacts, and the pairsof contacts being arranged in an electrical control circuit wherebybridging either pair of contacts closes the circuit.

2'. In an acceleration responsive device, longitudinally spaced blocksadapted for oscillation, a sphere normally resting and depending betweenproximate ends of the blocks, means for adjustiing the resting space forthe sphere betweenthe blocks, the sphere being adapted for dislodgmentfrom its normal inoperative position responsive to predeterminedacceleration of the blocks, so as to roll along one or the other of theblocks to operative position, and a control adapted for actuation byrolling the sphere to operative position.

3. In an acceleration responsive device, supporting means adapted foroscillation with the walking beam, the upper surface of the supportingmeans being transversely slotted intermediate its ends andlongitudinally grooved with a recess on either side of the transverseslot, means for adjusting the depth of the slotted portion, a spherenormally resting in said slotted portion, and a pair of transverselyspaced electrical contacts projecting into each recess, the sphere beingadapted for dislodgment from its normal inoperative position responsiveto predetermined acceleration of the walking beam and the supportingmeans, so as to roll along the groove and into one or the other of therecesses for bridging a pair of the contacts, and the pairs of contactsbeing arranged in an electrical circuit which controls the drivingmechanism for the walking beam, whereby bridging either pair of contactscloses the eleotrical circuit and stops the driving mechanism.

4. In an acceleration responsive device, longitudinally spaced supportsadapted for oscillation, the upper surface of each of said supportsbeing longitudinally grooved with a recess at the outer end, a spherenormally resting in inoperative position between said spaced supportsbut adapted to roll along said grooved surface of either of saidsupports to operative position into a recess in response to apre-determined acceleration of said supports, means for adjusting thespacing between said supports, an electrical control circuit, and meansfor controlling the electrical circuit by rolling the sphere tooperative position into either of said recesses.

JAMES P. BRANDT.

